Android學習筆記---自訂TextView實現陰影製作效果

標籤：文本   最佳化   技術   ret   處理   isp   shader   match   依賴   

直接上代碼

SGTextView.java

 1 package com.example.tv.view; 2  3 import android.content.Context; 4 import android.graphics.Canvas; 5 import android.graphics.Color; 6 import android.graphics.LinearGradient; 7 import android.graphics.Paint; 8 import android.graphics.Shader; 9 import android.graphics.Shader.TileMode;10 import android.util.AttributeSet;11 import android.widget.TextView;12 13 public class SGTextView extends TextView {14     private Paint strokPaint = new Paint();15     private Paint gradientPaint = new Paint();16 17     public SGTextView(Context context) {18         this(context, null);19     }20 21     public SGTextView(Context context, AttributeSet attrs) {22         super(context, attrs);23     }24 25     public void setStyle(String strokeColor, String startColor,26             String endColor, float strokewidthDp, int gradientHeighDp) {27         setStyle(28                 Color.parseColor(strokeColor),29                 DimensUtils.dip2px(getContext(), strokewidthDp),30                 new LinearGradient(0, 0, 0, DimensUtils.dip2px(getContext(),31                         gradientHeighDp), new int[] {32                         Color.parseColor(startColor),33                         Color.parseColor(endColor) }, null, TileMode.CLAMP));34     }35 36     public void setStyle(int strokeColor, float strokewidth, Shader shader) {37 38         strokPaint.setAntiAlias(true);39         // 設定是否使用映像抖動處理，會使繪製出來的圖片顏色更加平滑和飽滿，映像更加清晰40         strokPaint.setDither(true);41         // 如果該項設定為true，則映像在動畫進行中會濾掉對Bitmap映像的最佳化操作，加快顯示42         // 速度，本設定項依賴於dither和xfermode的設定43         strokPaint.setFilterBitmap(true);44 45         strokPaint.setStrokeWidth(strokewidth);46         strokPaint.setColor(strokeColor);47         // 設定繪製時各圖形的結合方式，如凹凸貼圖等48         strokPaint.setStrokeJoin(Paint.Join.ROUND);49         // 當畫筆樣式為STROKE或FILL_OR_STROKE時，設定筆刷的圖形樣式，如圓形樣式50         // Cap.ROUND,或方形樣式Cap.SQUARE51         strokPaint.setStrokeCap(Paint.Cap.ROUND);52         strokPaint.setStyle(Paint.Style.STROKE);53 54         gradientPaint.setAntiAlias(true);55         gradientPaint.setDither(true);56         gradientPaint.setFilterBitmap(true);57         gradientPaint.setShader(shader);58         gradientPaint.setStrokeJoin(Paint.Join.ROUND);59         gradientPaint.setStrokeCap(Paint.Cap.ROUND);60         gradientPaint.setStyle(Paint.Style.FILL_AND_STROKE);61 62         float textsize = getTextSize();63         strokPaint.setTextSize(textsize);64         gradientPaint.setTextSize(textsize);65 66     }67 68     public void setShadowLayer(float radius, float dx, float dy, String color) {69         strokPaint.setShadowLayer(radius, dx, dy, Color.parseColor(color));70     }71 72     @Override73     protected void onDraw(Canvas canvas) {74 75         String text = getText().toString();76         int width = getMeasuredWidth();77         if (width == 0) {78             measure(0, 0);79             width = (int) (getMeasuredWidth() + strokPaint.getStrokeWidth() * 2);80             setWidth(width);81         }82 83         float y = getBaseline();84         float x = (width - strokPaint.measureText(text)) / 2;85 86         canvas.drawText(text, x, y, strokPaint);87         canvas.drawText(text, x, y, gradientPaint);88     }89 }

DimensUtils.java

 1 package com.example.tv.view; 2  3 import android.content.Context; 4  5 public final class DimensUtils { 6     private DimensUtils() { 7     } 8  9     public static int px2dip(Context context, float pxValue) {10         final float scale = context.getResources().getDisplayMetrics().density;11         return (int) (pxValue / scale + 0.5f);12     }13 14     public static int dip2px(Context context, float dipValue) {15         final float scale = context.getResources().getDisplayMetrics().density;16         return (int) (dipValue * scale + 0.5f);17     }18 19     public static int px2sp(Context context, float pxValue) {20         final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;21         return (int) (pxValue / fontScale + 0.5f);22     }23 24     public static int sp2px(Context context, float spValue) {25         final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;26         return (int) (spValue * fontScale + 0.5f);27     }28 29 }

 

下面在布局中使用它

1         <com.example.tv.view.SGTextView2             android:id="@+id/tv_tishis"3             android:layout_width="wrap_content"4             android:text="換台中"5             android:layout_height="match_parent"6             android:textSize="15sp"7             android:gravity="center"8             android:visibility="gone"9             android:layout_centerHorizontal="true" />

 

在代碼中設定顏色以及陰影

1         tvMainPeogressBar = (SGTextView) findViewById(R.id.tv_tishis);2         tvMainPeogressBar.setTextSize(43);//字型大小3         tvMainPeogressBar.setText("換台中……");//常值內容4         tvMainPeogressBar.setStyle("#ded8cd", "#7d7a74", "#a1969d", 3, 9);//漸層顏色5         tvMainPeogressBar.setShadowLayer(2, 0, 2, "#000000");//陰影

Android學習筆記---自訂TextView實現陰影製作效果